Straight-bar knitting machine



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STRAIGHT-BAR KNITTING MACHINE Filed April 3,1945 2 sheets-sheet 1 l l I- I n I I. I f Wren/To)? y Harry W. 5 few-84 1 arch 12, 1946. w, ST RT r AL STRAIGHT-BAR KNITTING MACHINE 2 Sheets-Sheet 2' Filed April 3, 1945 Fig 2).

Patented Mar. 12, 1946 STRAIGHT-BAR KNITTING MACHINE Harry Wilfred Start, Carlton, and Ernest Start,

Wilford, England, assignors to George Blackburn and Sons Limited, Nottingham, England Application April 3, 1945, Serial No. 586,328 In Great Britain November 17, 1943 6 Claims.

This invention relates to improvements in straight-bar knitting machines and refers to improvements in the mechanism for driving the thread carriers of such machines.

In straight-bar knitting machines the thread carriers are connected to a driving bar which is reciprocated between end stops which are adjusted in well known manner from time to time in order to vary the traverse of the thread carriers so that the fabric produced by the machine may be shaped as desired.

The object of the present invention is to provide a positive drive to the thread carrier driving 1 bar which is automatically engaged and disengaged at the appropriate time, and so obviate the use of friction drive with its attendant drawbacks, and is preferably arranged so that it will move the driivng bar from rest up to its maximum velocity by an increasing acceleration after engagement and will bring the driving bar from its maximum velocity to rest with an increasing deceleration before disengagement.

According to this invention the reciprocating thread carrier driving bar is driven by a catch mounted on a reciprocated member and moved into and released from engagement with the thread carrier driving bar by a cam or the like moved relatively to the catch at the appropriate time. The member carrying the catch is preferably driven by means adapted to bring it to rest or practically to rest at the time the catch is disengaged from or engaged with the thread carrier driving bar and means are provided to vary the position where the bar carrying the catch is brought to rest or practically to rest so as to vary the traverse of the thread carrier driving bar as may be necessary from time to time to shape the work produced on the machine.

The invention will now be more particularly described with reference to the accompanying drawings in which:

Fig. 1 is a view showing, more or less diagrammatically for clearness, thread carrier bar driving mechanism constructed according to this invention in its normal operative position.

Fig. 2 is a view showing the driving connection disengaged at one end of the thread carrier bar traverse.

Fig. 3 is a view showing the driving connection disengaged at the other end of the thread carrier bar traverse.

' Fig. 4 is a front elevation and Fig. 5 a sectional side elevation of the control cam.

Like letters indicate like parts throughout the drawings.

In carrying out this invention a thread carrier driving bar A is carried in bearings disposed at suitable points in the machine. riers B, that isone for each knitting head in the machine, may be mounted on this driving bar A but preferably for convenience in construction the thread carriers'B are mounted on a separate bar 0 which is connected to and driven by the driving bar A in well known manner by a bolt D.

The driving bar A is reciprocated to drive the thread carriers B by a catch E adapted to engage with the bar A and carried by a reciprocating member F. The catch E is provided at a convenient point thereon with a lateral extension or nose E which engages between abutments E on the thread carrier" driving bar A to drive the latter.

It is well known that the traverse of the thread carriers in a straight-bar knitting machine is varied from time to time to shape the work produced on the machine. It will therefore be seen that the traverse of the thread carrier driving bar A must be varied to vary the traverse of the thread carriers. A variation in the traverse of the driving bar A is obtained by an alteration in the position where the catch E disengages from the driving bar A at each end of its traverse. The release of the catch E from engagement with the abutments E on the driving bar A when the latter reaches the end of its traverse and the reengagement of the catch E therewith at the start of the next traverse is controlled by a cam which engages with and is moved relatively to the catch E at the appropriate time.

The cam is preferably in the form of a slot G formed in a plate H mounted on a slide K which is reciprocated in any convenient manner and substantially to the same extent as the slur bar of the machine. Disposed on the catch E previously described is an anti-friction roller J which rides in the slot G and the latter is shaped with a depressed part in the centre. The depression provided in the centre of the slot G is of such a depth that when the anti-friction roller J on the catch E is riding in said depression as shown in Fig. 1 the catch E is in its engaging position as shown and when the roller J is moved out of said depression towards either end of the slot G by a movement of the plate H relatively to the member F, and consequently, the catch E is moved into its disengaged position relatively to the thread carrier driving bar A, as shown in Figs. 2 and 3, the movement of the plate H relatively to the mem- The thread car-' ber F to effect the catchs engagement with or release from the driving bar A being eifected in the manner hereinafter described.

By the use of a cam in the form of a slot as shown in the drawings the catch E is positively moved into and out of engagement with the driving bar A and its movement is contro11ed by the shape of the slot so that it is effected without shocks and with the minimum amount of noise.

The member F on which the catch E is mounted is reciprocated by a driving connection between the member F and the slide 'K which carries the cam plate H. This driving connection is of such a nature that an adjustment thereof at the appropriate time will efiect an alteration in the relative positions of the slide K and member F and consequently between the cam plate H and the catch E. For this purpose the member F may be connected by a link to the end of an arm secured on an axle mounted in a bracket on the slide K, the axle being angularly adjusted in any convenient manner at the appropriate time to effect an alteration in the relative positions of the slide K and the member F. In the arrangement shown in the drawings the driving connection comprises a toothed rack L secured on the member F and engaged by a pinion M mounted on the slide K and normally held against movement so that the member F reciprocates with the slide K. It will be readily seen that by an angular movement of the pinion M, a movement of the member F relatively to the slide K is obtained and that by an angular movement of the pinion M in the appropriate direction during the movement of the slide K and that with suitable mechanism to control the movement of the pinion M, the member F can be momentarily brought to rest at any point within the limits of the distance travelled by the slide K.

In order to control the movement of the pinion M it is secured to one end of an axle N to the other end of which an arm is secured and the free end of this arm 0 is provided with an anti-friction roller P which rides in a cam slot disposed in a plate Q attached to the fixed framing of the machine, the roller P moving backwards and forwards along the cam slot as the slide K reciprocates. The cam slot comprises a central straight portion R the ends of which are connected by substantially inclined portions R R with downwardly and upwardly ofl'set straight portions T, T arranged parallel with but on opposite sides of thecentral portion R and disposed so that the inclined portions R R will move the arm 0 so that the pinion M is moved in a clockwise direction when the slide K is moving from left to right and will move the pinion M in the reverse or anticlockwise direction when the slide K is moving from right to left. The inclined portions R R are shaped so that the movement of the pinion M is suflicient to bring the member E, driven thereby, momentarily to rest and accelerate it again up to normal speed as the roller P passes through the inclined portions R R of the cam Islot, whichever direction the slide K is travel- The arrangement works in the following manner.

As the slide K reciprocates, the member F carrying the catch E will be reciprocated thereby and as the roller P on the arm 0 associated with the pinion M passes along the inclined portions R R of the cam slot the pinion M will be angularly adjusted to bring the member F momentarily to rest. This alteration in the motion of the member F alters the relative positions of the catch E and the catch controlling cam plate H carried by the slide K. It will therefore be seen that by a suitable disposition of the various parts the member F carrying the catch E can be brought to rest and the catch E released at points in the traverse of the slide K corresponding to the positions of the inclined portions R R of the control cam and the thread carrier driving bar A brought to rest, the catch E and cam plate H being restored to their normal positions and the catch E re-engaged at the same points on the return motion of the slide K and the thread carriers B traversed backwards and forwards a distance depending on the distance between the inclined portions R R of the control cam.

For example when the mechanism is in its normal driving position as shown in Fig. 1 and the slide K is moving from left to right, the thread carrier driving bar A will move from left to right, the thread carriers B moving therewith. When the anti-friction roller moves into the part R of the control cam, the pinion M is moved in a clockwise direction. The part R is shaped so that as the roller P passes from the part R of the control cam through the part R into the part T the pinion is adjusted in a clockwise direction so as to bring the member F from its normal speed, that is the speed of the slide K, momentarily to rest or practically to rest and back again to its normal speed as the roller P enters the part T. The movement of the pinion M as described causes a movement in the member F relatively to the slide K and consequently a movement of the cam plate H relatively to the roller J on the catch E. The cam slot G is shaped so that the catch E is moved out of engagement with the abutments E on the driving bar A at the moment when the member E is momentarily at rest or practically at rest. As a result the driving bar A and consequently the thread guides will be brought to rest at the moment the member F is brought to rest or practically to rest and will remain in this position as the member F continues on its further motion from left to right, the catch E being retained in its disengaged position during this further motion. On the return motion of the slide K the roller P will pass from the part T of the control cam through the part R into the part R. As the roller passes through the part R the pinion is turned in the reverse direction and the parts restored to their normal positions and the catch E reengaged with the driving bar A which is traversed from right to left until the roller enters the part R of the control cam when the catch E will be disengaged in a similar manner to that described.

In the drawings the member F is shown as driven from the upper side but it will be understood that it can be driven if desired from the underside, in which case the shape of the control cam must be reversed so as to move the pinion M in the appropriate direction at the required moments.

In order to vary the traverse of the thread carriers B the control cam is made in two parts U, V, see Fig. 4 so that the central straight portions R and consequently the distance between the inclined portions R R can be lengthened or shortened as desired, suitable mechanism similar to that normally provided to adjust the carrier bar end stops being provided to make the necessary adjustment of the two parts U, V, at the appropriate time.

The slowing down to rest of the catch driving member F as the catch E is disenga ed from the thread carrier driving bar A and its motion from rest up to normal speed after the catch E is reengaged gives a corresponding motion to the thread carriers B. In order to prevent the slur cocks of the machine overrunning the thread carriers at each end of their traverse the thread carriers are given a sufficient lead in front of the slur cocks and this is effected by timing the driving mechanism of the reciprocating slide K so that the latter moves sufilciently in advance of the slur cocks to give the necessary lead to the thread carriers. For this purpose a separate draw mechanism to drive the slide K may be provided.

With the construction described and illustrated in the drawings it will be seen that if, when the machine is standing, the driving bar A is moved longitudinally for any purpose when the catch E is in its disengaged position and not returned to its correct position, then when the machine is started the catch E will not engage between the abutments E and damage may be done to the machine. To obviate this possibility the bolt D may be carried by a friction box mounted on the driving bar A and the part E or nose of the catch E carried so that it is held in its operative position by a spring. Alternatively the cam plate H may be mounted so that it can slide against the action of a spring in the event of the driving bar A becoming displaced. In this event on starting the machine the catch E will move into its operative position in the normal way and will move until it engages with the side of one of the abutments E when the part E will ride up the sides of the abutment and move into its proper position between them when the driving bar A will then be driven in the correct manner.

With the arrangement described the thread carrier driving bar is positively driven and is automatically brought to rest at each end of its traverse by the driving mechanism so that impact of the thread carrier bar on its end stops is reduced to the minimum and the carrier bar is started from rest and moved up to its maximum speed with an increasing acceleration. As a result the strain of starting and stopping the thread carrier bar each motion is reduced to the minimum with a consequent reduction in wear and tear whilst permitting the machine to be run faster and a corresponding greater output obtained therefrom in a given time.

What we claim as our invention is:

1. Mechanism for driving the thread carriers of straight-bar knitting machines comprising in combination a thread carrier driving bar, a catch mounted on a bar to engage with the-driving bar, a catch operating cam mounted on a reciprocating slide, a driving connection between the reciprocating slide and the catch bar and means to move the cam relatively to the catch at the appropriate time to move the catch into engagement with or disengage it from the driving bar.

2. Mechanism for driving the thread carriers of straight-bar knitting machines comprising in combination a thread carrier driving bar, a catch mounted on a bar to engage with the driving bar, a catch operating cam mounted on a reciprocating slide, a pinion mounted on the slide and engaging with a rack secured to the catch bar and means to angularly adjust the pinion at the appropriate time to adjust the relative positions of the cam and catch to move the latter into engagement with or disengage it from the driving bar.

3. Mechanism for driving the thread carriers of straight-bar knitting machines comprising in combination a thread carrier driving bar, a catch mounted on a bar to engage with the driving bar,

a catch operating cam mounted on a reciprocating slide, a pinion on an axle carried by a bracket mounted on the slide, a rack on the catch bar engaging with the pinion, an arm on the pinion axle and a roller on the arm engaging in a cam slot shaped so as to angularly adjust the pinion at the appropriate times to adjust the relative positions of the cam and catch to move the catch into engagement with or disengage it from the driving bar.

4. Mechanism for driving the thread carriers of straight-bar knitting machines comprising in combination a thread carrier driving bar, a catch mounted on a bar to engage with the driving bar, a catch operating cam mounted on a reciprocating slide, a pinion on an axle carried by the slide, a rack on the catch bar engaging with the pinion, an arm on the pinion axle and a roller on the arm engaging in a cam slot comprising a central straight portion, adjustable in length,

the ends of the straight portion leading into extensions parallel with the central portion but disposed on opposite sides thereof.

5. Mechanism for driving the thread carriers of straight bar knitting machines comprising in combination a thread carrier driving bar, a catch pivoted on a bar to engage with the driving bar, a roller on the catch engaging in a cam slot in a plate carried by a reciprocating slide, a driving connection between the reciprocating slide and catch bar and means to move the cam slot relatively to the roller at the appropriate times to move the catch into engagement with or disengage it from the driving bar.

6. Mechanism for driving the thread carriers of straight-bar knitting machines comprising in combination, thread carriers mounted on a bar, a driving bar connected thereto, a catch mountted on a bar to engage with the driving bar, a catch operating cam mounted on a reciprocating slide, a driving connection between the reciprocating slide and catch bar and means to adjl lst the relative positions of the cam and catch at the appropriate times to move the catch into engagement with or disengage it from the driving bar.

HARRY WILFRED START. ERNEST START. 

